Gents, has anyone ever chronographed the muzzle velocity of federal tru 64 grain sp out of a 10.5 barrel with 1/9 twist?   Would be a big help.

EDA: A nice guy at the range let me run 10 rounds through his chrono.  Below are the number.
Avg: 2368
Hi: 2412
Low: 2333
Extreme Spread: 78.8
Standard Dev: 24.4
Average Dev: 18.4

This was out of a factory Rock River SBR, 10.5", 1/9 twist, Chrome lined barrel,
65 degrees outside, 160 elevation

Enjoy

BTT with actual numbers

Here is some chrono results from my 10.3" DD 1/7 twist barrel. Using IMI M855

IMI Factory 5.56 62gr SS109 FMJ
Average2655.9
High2682
Low2618
Standard Deviation19.19172275
Extreme Spread64
Energy971.3395039


12618
22662
32669
42654
52668
62638
72661
82682
92638
102669